Stimulation of p-nitroanisole O-demethylation in perfused livers by xylitol and sorbitol

Xylitol and sorbitol, two sugar alcohols which readily enter into pathways of hepatic carbohydrate metabolism, stimulated p-nitroanisole O-demethylation in perfused livers from fasted, but not fed, phenobarbital-treated rats. The increase in mixed-function oxidation correlated well with the production of NADH from the metabolism of xylitol and sorbitol (half-maximal stimulation for both processes was observed with concentrations between 0.1 and 0.2 mM). p-Nitroanisole metabolism by isolated hepatic microsomes was unaffected by the addition of xylitol and sorbitol; however, when NADH was added to microsomes, or was generated from sorbitol, sorbitol dehydrogenase and NAD⁺, a synergistic increase in p-nitroanisole metabolism occurred. Ethanol (0.2 mM), which does not enter into pathways of carbohydrate metabolism, also caused an increase in the pyridine nucleotide redox state and stimululated p-nitroanisole O-demethylation in livers from fasted rats. In addition, sorbitol and xylitol stimulated p-nitrophenol conjugation in livers from fasted, phenobarbital-treated animals, probably by supplying substrate for increased UDP-glucuronic acid synthesis. The data indicate that sugars which influence the pyridine nucleotide redox state alter rates of mixed-function oxidation and conjugation in whole cells.     

Detailed caliceal anatomy for endourology

A thorough understanding of caliceal anatomy is required to interpret excretory urograms and to perform safely endourological manipulations. Caliceal angles, posterior rotation of the lateral renal margin and caliceal placement in relation to the lateral aspect of the body were studied in 26 right and 24 left kidneys. Differences between kidneys found to be Br?del's types from those of the Hodson type, and the significance of these findings for performing nephrostolithotomy are described.     

Aortoiliac dissection due to aortic cannulation

A case of acute aortoiliac dissection due to cannulation of the ascending aorta for extracorporeal circulation is reported. Although this patient was proved to have cystic medial necrosis, the exact cause of the dissection is not known. It is suggested that insertion of the cannula perpendicular to the aorta with penetration of all aortic layers may help to minimize this problem. Other patients with dissection of the ascending aorta are reviewed, and the central role of cystic medial necrosis as a causative factor is stressed.     

Sequence and expression of the glycosyl-phosphatidylinositol-specific phospholipase C of Trypanosoma brucei

Trypanosoma brucei contains a membrane-bound phospholipase C which converts the variant surface glycoprotein (VSG), anchored in the membrane by a C-terminal glycosyl-phosphatidylinositol moiety, into a soluble form and diacylglycerol. The amino acid sequence (358 residues) of this enzyme, derived from the nucleotide sequence of the cDNA and the gene, reveals a polypeptide which lacks an obvious N-terminal signal sequence and stretches of exclusively hydrophobic residues. These properties suggest that the phospholipase is synthesized in the cytoplasm and subsequently associates with or translocates across intracellular membranes. There are much higher levels of glycosyl-phosphatidylinositol specific phospholipase C mRNA in bloodstream form than in procyclic form trypanosomes. The phospholipase gene is probably present in one or two copies per haploid genome, probably not associated with VSG expression sites.     

Postoperative chylothorax in children with congenital heart disease. Clinical and roentgenographic features.

The clinical and roentgenographic findings in 11 children were reviewed following development of a chylothorax after surgery for the management of congenital heart disease. The operative site in most cases was in proximity to the aortic isthmus. The pleural effusion was delayed in onset, reaccumulated rapidly after initial thoracentesis, and frequently recurred after apparent resolution. In most patients, widening of the mediastinum was noted prior to the appearance of the pleural effusion. Anatomical features of the thoracic duct and pathophysiologic concepts operative in chylothorax are reviewed and related to the clinical and roentgenographic characteristics of this entity.